[ovs-discuss] Issue with vlan tag being changed after reboot of KVM hypervisor.

[Ben Pfaff]

I'd start by looking at the history of the OVS database.  You can run
        ovsdb-tool -mm show-log /etc/openvswitch/conf.db
to see everything that has modified the database since it was
initialized, with comments, in chronological order.  You should pipe it
through "less" or another pager, because it will produce a lot of
output.  Probably, you'll see some change to the tag column.

(Possibly the database is in some other location but the file name above
is a good guess.)

On Wed, May 18, 2016 at 10:57:03AM -0600, Pippin Wallace wrote:
> Ben, thanks for the reply.  I honestly don't know what would cause this as
> the tags are set correctly and work just fine until the host system is
> rebooted.
> 
> I would love to help investigate this further so please let me know what
> you would suspect or if you need any additional details.
> 
> Regards -- Pippin
> 
> On Tue, May 17, 2016 at 8:05 PM, Ben Pfaff <blp at ovn.org> wrote:
> 
> > On Mon, May 16, 2016 at 04:08:53PM -0600, Pippin Wallace wrote:
> > > First off I apologize for submitting a "bug" on such an old version but
> > > what I am trying to find is the first "stable" OVS version where this bug
> > > is fixed and move it it for now.
> > >
> > >
> > >
> > > The situation is that the majority of our VM's running under KVM will
> > have
> > > changed vlan tags when the physical host is rebooted.
> > >
> > >
> > >
> > > For example after a reboot one of the VM's will have the correct vlan tag
> > > via "virsh dumpxml <domain>" but when we check with "ovs-vsctl list port
> > > <vnet#>" we will see the wrong tag listed there.  We have been resetting
> > > the tags with "ovs-vsctl set port vnet# tag=#" but are looking for a
> > "fix"
> > > or the correct way to set our tags if that is the problem here.
> >
> > Do you have a reason to believe that this is a bug in OVS?  I don't
> > recall a bug like this in OVS, so it may be a bug in whatever is setting
> > up the tag.
> >